Clinicopathological characteristics and prognosis of patients with adenosquamous lung carcinoma

Tumor Location and Survival Outcomes in Lung Adenosquamous Carcinoma: A Propensity Score Matched Analysis

Background

There is little information in the literature available on lung adenosquamous carcinoma (LASC). The association between tumor location and survival outcomes in LASC is poorly understood. Our study was designed to probe the effect of tumor location on survival outcomes of LASC.

Material/Methods

Patients with LASC between 2004 and 2015 were identified using the Surveillance, Epidemiology and End Results (SEER) databases. The patients were divided into 2 groups, a main bronchus group and a peripheral group, according to their primary sites. The Propensity Score Matching (PSM) method was used to reduce possible bias between groups. The primary endpoints were overall survival (OS) and cancer-specific survival (CSS).

Results

A total of 3176 patients, afflicted with LASC between 2004 and 2015, were extracted from the SEER databases. Of these, 212 patients were found to be eligible for analysis after a propensity 1: 1 nearest neighbor matched analysis. After PSM, multivariate Cox regression analysis showed that primary site, American Joint Committee on Cancer (AJCC) stage, T stage and surgery were independent predictors of LASC in both OS and CSS. Kaplan-Meier survival analysis showed that patients with LASC located in a peripheral site had better survival outcomes than those with LASC located in the main bronchus. In subgroup analysis, the advantages of tumor located in a peripheral site were more pronounced in female patients and AJCC stage I patients.

Conclusions

Tumor location may have an impact on the survival outcomes of patients with LASC. Patients with LASC located in a peripheral site had better survival outcomes than patients with LASC located in the main bronchus, particularly in female patients and AJCC stage I patients.

Research progress of the clinicopathologic features of lung adenosquamous carcinoma

Adenosquamous carcinoma (ASC) of the lung, a biphasic malignant tumor arising from lung tissue, is a special subtype of non-small-cell lung cancer (NSCLC) with low incidence but high tendency of invasion and poor prognosis. ASC contains components of lung adenocarcinoma (AC) and lung squamous cell carcinoma (SCC). However, there is a remarkable difference between ASC and other NSCLCs in clinical features, suggesting that ASC is not a simple mixture of AC and SCC, but is rather a more complex carcinoma with a unique molecular phenotype. At present, the research on ASC is still rare, mostly because of its complicated molecular mechanism and unclear pathological origin. The lack of cognition of ASC limits its early diagnosis and treatment, and a set of mature and effective treatment programs has not been proposed yet. In-depth study of the molecular characteristics and clinical features of ASC will not only help to better understand the scientific issues, including phenotype switching of lung cancer, the origin of tumor development, and tumor heterogeneity, but also contribute to the development of its individualized treatment. This review summarizes the recent studies concerning the clinicopathologic features and the molecular mechanisms of ASC to further facilitate the development of its individualized treatment.

Predictive and prognostic value of preoperative serum tumor markers in resectable adenosqamous lung carcinoma

Background

Adenosquamous carcinoma is a rare and aggressive form of lung cancer. The prognostic and predictive value of preoperative serum tumor markers and frequency of EGFR mutations in adenosquamous lung carcinoma are unclear.

Methods

We retrospectively analyzed data and samples collected from 106 radically resected adenosquamous lung carcinoma patients with pathological stage I-IIIA between 2008 and 2013. Correlations between serum tumor marker levels and EGFR mutations as well as survival parameters were analyzed and prognostic factors were identified.

Results

Of the 106 adenosquamous lung carcinoma patients, 29 (27.4%) harbored EGFR mutations. By univariate analysis, advanced clinical stage (P = 0.009 for disease-free survival [DFS]; P = 0.046 for overall survival [OS]), larger tumor size (P = 0.001 for DFS; P = 0.002 for OS), regional lymph node metastasis (P = 0.024 for DFS; P = 0.030 for OS), higher NSE level (P = 0.002 for DFS; P < 0.001 for OS), and higher TMI (tumor marker index) (P = 0.009 for OS) were significantly correlated with a worse prognosis. By multivariate analysis, NSE (P = 0.014) was confirmed as independent predictor for DFS, while NSE (P = 0.001) and TMI (P = 0.038) were independent prognostic factors for OS.

Conclusion

Adenosquamous lung carcinoma is an aggressive malignancy with relatively high EGFR mutation frequency. Elevated preoperative NSE level and TMI are adverse predictive and prognostic indicators.

Lkb1 inactivation drives lung cancer lineage switching governed by Polycomb Repressive Complex 2

Adenosquamous lung tumours, which are extremely poor prognosis, may result from cellular plasticity. Here, we demonstrate lineage switching of KRAS+ lung adenocarcinomas (ADC) to squamous cell carcinoma (SCC) through deletion of Lkb1 (Stk11) in autochthonous and transplant models. Chromatin analysis reveals loss of H3K27me3 and gain of H3K27ac and H3K4me3 at squamous lineage genes, including Sox2, ΔNp63 and Ngfr. SCC lesions have higher levels of the H3K27 methyltransferase EZH2 than the ADC lesions, but there is a clear lack of the essential Polycomb Repressive Complex 2 (PRC2) subunit EED in the SCC lesions. The pattern of high EZH2, but low H3K27me3 mark, is also prevalent in human lung SCC and SCC regions within ADSCC tumours. Using FACS-isolated populations, we demonstrate that bronchioalveolar stem cells and club cells are the likely cells-of-origin for SCC transitioned tumours. These findings shed light on the epigenetics and cellular origins of lineage-specific lung tumours.

The mechanisms that govern the transdifferentiation of lung adenocarcinomas (ADC) to squamous cell carcinoma (SCC) are not fully understood. Here, the authors show that EZH2 loss exacerbates the transdifferentiation of ADCs to SCCs as a result of chromatin changes that lead to expression of squamous differentiation genes.

Improved survival associated with a balanced structure between adenomatous and squamous components in patients with adenosquamous carcinoma of the lung

BACKGROUND

Primary adenosquamous carcinoma (ASC) of the lung is rare and its biological behavior has not yet been thoroughly described. The aim of this study was to analyze the clinicopathological characteristics and prognostic factors associated with ASC.

MATERIALS

Clinical records of patients with ASC of the lung who underwent surgery between October 2008 and December 2014 in a single institution were retrospectively reviewed.

RESULTS

A total of 205 patients were identified. Patients with balanced structural components had significantly better prognosis than those with squamous (p = 0.014) or adenomatous (p < 0.001) predominance, and those with N0, N1, and N2 ASC (N0 vs. N1 [ p = 0.031] and N1 vs. N2 [p = 0.037], respectively), or stage I, II and IIIA ASC (stage I vs. II [p = 0.021] and stage II vs. IIIA [p = 0.007], respectively) had significant differences with respect to overall survival (OS). Multivariate analysis identified structural components (p = 0.011), tumor, node and metastasis (TNM) status (p < 0.001), and adjuvant chemotherapy (p = 0.008) as significantly prognostic factors for OS, and structural components (p = 0.030), TNM stage (p < 0.001) and adjuvant chemotherapy (p = 0.005) as the corresponding variables for disease-free survival.

CONCLUSIONS

A balanced structure between adenomatous and squamous components in patients with primary ASC of the lung was associated with better prognosis.